A probe card is an assembly of components used together to test integrated circuits that are formed on a silicon wafer. Such probe cards provide an interface between the testing equipment and the integrated circuit patterned on the silicon wafer. Such probe testing is performed before a semiconductor device is shipped to a customer. To test a given semiconductor die of the silicon wafer, a probe card is positioned over each die of the wafer. Probe needles on the card touch corresponding bond pads on the die. The needles act as transmitters, electronically sending information to and receiving information from the die's memory. The tests performed by the probe save packing and test costs by testing the semiconductor die prior to packaging, and further help to increase yields by allowing for repairs of some of the non-functional die and by providing data for yield analysis and enhancement.
In current probe tests for NOT AND (NAND) type integrated circuits such as NAND flash memory, a reduce low pin count (RLPC) interface is used with single data rate testing. NAND flash memory circuits have experienced a rapid increase in memory density and storage capacity. As the density of transistors that are fabricated on a NAND semiconductor device increases, the loading times and unloading times of parallel probe testing of such high density devices increase. State of the art NAND devices may take days to be tested, and test time increases with capacity. It would therefore be beneficial to be able to increase testing rates while providing minimal hardware changes to the RLPC circuit.
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.